1. Field of the Invention
The present invention relates to a power-supply device and, in particular, to a power-supply device for generating an internal power-supply voltage from an externally-provided power supply, a method for controlling the power-supply device, and a communication device including the power-supply device.
2. Background Art
As a power-supply device formed in a semiconductor integrated device, a power-supply device including: a power-supply circuit for operation which becomes active in a normal operation; and a standby power-supply circuit which becomes active in a standby state has been proposed (see Japanese Patent Application Laid-Open No. 2002-373942, for example). In such a power-supply device, upon being switched from the normal operation to the standby state, the power-supply circuit for operation stops its operation and the standby power-supply circuit starts its operation instead of the power-supply circuit for operation. Japanese Patent Application Laid-Open No. 2002-373942 describes that a power-supply voltage generated in the standby power-supply circuit is lower than a power-supply voltage generated in the power-supply circuit for operation.